A laptop computer containing Social Security numbers of more than 98, 000 graduate students, graduate school applicants and other individuals was stolen two weeks ago from an unlocked office at UC Berkeley, campus officials said Monday.

There is no evidence that the personal data was retrieved or misused, said UC Berkeley spokeswoman Marie Felde.

In line with a 2002 state law requiring public notification of large data leaks, the campus is attempting to notify all those whose personal information was in the computer. Also, to address the possibility of identity theft, Cal officials are suggesting that affected people consider placing a fraud alert on their credit-reporting accounts.

The incident is the third serious data breach at UC Berkeley within the past two years and the latest of several recent compromises of personal information across the country that are prompting calls for tougher data protections.

The campus waited two weeks before publicly revealing the theft because "police believed they had a much better chance of recovering the stolen laptop if we didn't announce it immediately," Felde said. The computer has not been found or the thief identified, she said.

The data was on a new IBM laptop stolen from an employee's office in the Graduate Division on March 11, Felde said. A campus employee spotted what appeared to be the thief leaving with the computer and contacted police, according to Felde.

The theft occurred during the lunch hour when the normally locked door to the office was unintentionally left unlocked, Felde said.

The data had just been downloaded into the computer the day before and was scheduled to be encrypted -- making sensitive personal information unreadable to outsiders -- later in the afternoon of the day of the theft, Felde said.

"It was just unbelievably rotten luck," Felde said.

The computer contained names and Social Security numbers of 98,369 people, including "most individuals who applied to graduate school at UC Berkeley between fall 2001 and spring 2004 (except law students); graduate students who enrolled at UC Berkeley between fall 1989 and fall 2003; recipients of doctoral degrees from 1976 through 1999; and other small groups of individuals, " according to a campus news release.

About a third of the computer's files also contained dates of birth and/or addresses, according to the campus.

It has also set up a hot line at (800) 372-5110, open Monday-Friday between 8 a.m. and 6 pm. for those seeking more information or wanting to know whether their data was in the laptop.

Questions can also be sent by e-mail to idalert@berkeley.edu. More information is available at on the Web at newscenter.berkeley. edu/security/grad/.

Anyone with information about the theft is urged to contact UC Berkeley police at (510) 642-6760. The theft suspect was described as an African American female, about 5 feet 6 inches tall, around 185 pounds, in her 40s, and wearing casual clothing, Felde said.

The Graduate Division is taking steps to tighten security of its data, including encryption and increased staff training, Felde said. The entire campus is in the process of encrypting such data as a result of a UC systemwide directive last fall, she said.

The two earlier major data-security breaches at Cal were attributed to hackers. Last August, a hacker broke into the private computer of a visiting researcher on campus. The computer contained Social Security numbers and other personal data for about 600,000 participants in the state's In Home Supportive Services program.

Felde said state officials had not heard of any cases of identity theft from that break-in.

In August 2003, a hacker broke into a UC-maintained computer at the Bancroft Library containing driver's license numbers and other personal data of about 17,000 people.